Bit-forging machine



P 7, 1931- c. 1. ANGSTROM' 1,799,151

BIT FORGING MACHINE Filed June 20, 1928 3 Sheets-Sheet 1 fi fl flINVENTOR April 7, 1931. c. J. ANGSTROM 1,799,151

BIT FORGING MACHINE Filed June 20, 1928 5 Sheets-Sheet 3 Patented Apr.7, 1931 UNITED STATES CARL: J. ANGSTROM', 0F PITTSBURGH, PENNSYLVANIA,ASSIGNOR TO THE MARTIN PATENT OFFICE Q HARDSOCG GOMPAN Y, OF PITTSBURGH,PENNSYLVANIA, A CORPORATION OF PENN- SYLVAN IA Application filed June20,

This invention relates toinetal forging, and more particularly to theforging of cutter bits such as for instance, as the bits used in miningmachines. 7 i r The present invention has for its object to provide abitforging machine of an improved construction and capable of substantiallycontinuous operation.

The invention may be readily understood by reference to the accompanyingdrawings, in which Figure 1 is a top plan embodying my invention;

Figure 2 is a transverse vertical section in the planeof line IIII ofFigure 1;

Figure 3 is a detail view of a ratchet mechanism for driving themultiple die forging isk;

Figure 4 is a vertical section through the forging disk at right anglesto its axis;

' Figure 5 is atransverse vertical section through the forging disk inthe plane of line VV of Figure 4;;

Figure 6 is a detail elevation of oneof the shaping rollers'of themachine; and Figure 7 is a perspective view showing one of the cutterbits adapted to be forged in the machine. 7

In the drawings which show a preferred embodiment of the machine, 2designates the machine frame. Mounted on the frame is view of a machinea driving motor 3. The motor 3 has a gear 4 on its shaft, and this gearmeshes with a gear 5 of larger diameter mounted on the shaft 6. Theshaft 6 is continuously 'driven by the motor. On one end of theshaft '6is a pinion 7 which mesheswith a gear wheel 8 on a second shaft 9parallel to the shaft 6. The shaft 9 is continuously driven by the motor3 through the train of gears and thespeed is reduced through the gearratios.

Carried in bearings 10 on the frame of the machine is a heavy shaft 11which is parallel with the shaft 9 and on which is a Wheel or disk 12. V

The disk 12 has a dove-tailed slot 13 in the periphery thereof. Atintervals around the periphery of the disk, the disk is cut awav acrossits entire width, providing a series of shoulders 14. 'Set against theshoulders 14,

die blocks and four BIT-FORGING MACHINE 1928. Serial No. 286,864.

as best shown in Figure 4, are transverse blocks 15. These blocksprovide stop elements for die blocks 16 and die block holders 17. Thedie block holders 1'? are of the cross section best shown in Figure 5,having a bottom plate portion 1? and an under-cut flange 17 The dieblock 16 has an upstanding die portion 16 projecting beyond theperiphery of thedisk 12 and a flared or dove-tailed base portion 16received in the slot 13 and resting on the base portion'17 of the holder17. i

As best shown in Figure 5 the die block is clamped in place by reason ofthe fact that one side of the slot 13overhangs one side of the base 16and the overhanging portion 17 b of the holder 17 fits over the otherside of the base portion 16". A set screw 18 is provided in one sideofthe disk for holding the clamping member 17 in binding relation with thedie block. The die block has one end butting against the cross piece 15,as shown in Figure 4. Forwardly of each die block with reference to thedirection of rotation of the disk. the disk is cut away to form a pocket19 in which a holder 20 is retained by nates a length of cutter stock,and B designates a completed bit.

The die blocks 16 can be removed bv loosening the set screws 18 andslipping the blocks forwardly with reference to the direction ofrotation of the disk afterthe holder'20 has been removed from the pocket19. With this arrangement the die blocks can be conveniently replaced orrepaired when necessary.

I In the arrangement shown, there are four sockets 22. In the preferredembodiment of the invention the disk 12 is rotated in a step by stepfashion, being moved 90 'at each successive operation. For effectingthis step by step'rotation of the disk a ratchet wheel 23 is secured onone end of the shaft '11. This ratchet wheel has four teeth thereon.

Loosely mounted on the shaft 11 is a bifurcated lever 24:, one arm ofwhich is located at each side of the ratchet 23. On the lever 24 is apawl 25 having an actuating spring 26 which is adapted to engage theratchet teeth upon movement of the lever in the opposite direction. Thelever 24 is actuated by means of a connecting rod 27 having one endthereof pivotally secured to the lever 24 at 28 and having its other endsecured to the crank pin 29 on the face of the gear wheel 8. \Vith thisarrangement the ratchet wheel 23 is advancing through an arc of 90 witheach rotation of the gear wheel 8.

Supported on the frame 2 over the disk 12 is a lever 30 having a groovedforging roller 31, such as shown in Figure 6 at one end thereof. Thisroller has a groove 32 therein, which groove has a cross sectional shapesubstantially similar to the cross sectional shape of the die blocks 16.The roller 31 is adapted to ride on or close to the periphery of thedisk and is retained in the desired position by means of oppositelyarranged set screws 33 and 34 on the other end of the lever 30, theseset screws cooperating with a bridge element 2 on the frame 2. One ofthe set screws 33 holds the end of the lever from lifting away from thebridge 2 while the other set screw limits the movement of the end of thelever toward the bridge.

Pivotally mounted in the frame under the lever 30 is a second lever 35which is in the shape of a bell crank having two arms 35 and 35". Thislever is pivotally supported on a shaft 36. At the end of the arm 35 isi i a forging roller 37 similar to the roller 31.

On the shaft 36 and extending. under the arm 35 of the lever 35 is alever 38 having a roller 39 at its free end. On the arm 35" are setscrews 40 and 41 similar in function to the set screws 33 and 34,except, however, that these set screws instead of cooperating with afixed bridge on the frame of the machine, cooperate with the lever 38.

Parallel with the shaft 9 and located in a plane almost directly overthe shaft 9 is still another shaft 42. On the shaft 42 is a sprocketwheel 43. On the shaft 11 is a sprocket wheel 44. A chain passes aroundthe sprocket wheels 43 and 44 and serves to rotate the shaft 42intermittently with the shaft 11. The ratio of the sprocket Wheels 43and 44 is such, however, that the shaft 42 is rotated a completerevolution with each quarter revolution of the shaft 11. Carried on theshaft 42 is a cam 46 having a single high spot 46".

Ihe high spot on the cam is so located with reference to the disk 12that the cam will engage the roller 39 to lift the lever 38 just as thepartially formed cutter bit comes into engagement therewith and isarranged to relieve the pressure on the roller 39 just as the completedcutter bit moves out of engagement with the roller 37, as hereinaftermore fully described.

In the operation of the machine an operator standing at the end of themachine drops a length of metal A into each socket 22 as the disk 12 isrotated. In the particular machine shown the stock or length of toolsteel A moves through the first 90 without any operation being performedthereon. The stock is then in the position shown in Figure 4. With thenext 90 movement of the disk 12 the st7ock is carried under both therollers 31 and P) In passing under the first roller 31 the metal, whichis preferably hot, is forced over the die block 16 and shaped by thegroove 32. and made roughly to the shape of the finished bit. However,due to the fact that the metal is being moved through an are under theroller 31, the top of the bit is rounded instead of being flat in alongitudinal direction. By reference to Figure 7 it will be seen that itis desirable that the edge B of the cutter bit B be a straight line. Inpassing under the second roller 37 the metal is forged further toproduce a straight edge instead of a rounded edge. This is accomplishedby gradually depressing the roller 37 through the cam 46 from thebeginning of the point of contact of the partly forged cutter with theroller 37 to the point where the highest part of the bit is under theroller. After the highest part of the bit has passed under the rollerthe highest part of the cam 46 is passed out of engagement with the camfollower 39 and the roller 37 will engage the bit with graduallydecreasing pressure. By thus initially increasing the pressure from thebeginning to the high point of the bit and then decreasing the pressurefrom the high point to the end of the bit, a straight edge is forged onthe cutter notwithstanding the fact that the cutter is traveling throughan arc.

As the forging disk 12 continues to rotate the completed bits can dropout into a basket or other collecting means located beneath the disk 12.

lVith this arrangement the machine can operate continuously. By means ofthe set screws 33 and 34 and 40 and 41, the pressure of the rolls 31 and37 can be conveniently adjusted.

By reason of the fact that the disk 12 is rotated intermittently theoperator is given sufficient time to insert the lengths of metal fromwhich cutter bits are formed into the holding sockets. This can be donemore conveniently than if the disk 12 were a continuously rotating disk.

While I have described a preferred e1nbodiment of my invention, it willbe understood that the invention is not limited to the particularconstruction and arrangement shown but may be otherwise embodied.

I claim:

1. In a machine for the manufacture of cutter bits, a carrier diskhaving a bit receiving socket therein and having a die block thereonadjacent the socket, means for rotat ing the carrier, a forging rolleradapted to cooperate with the die block on the carrier, and a secondforging roller following the first, and means for moving the secondroller toward the carrier during a portion of the rotation of thecarrier and for moving the second roller away from the carrier duringthe next succeeding portion of the travel of the carrier by means ofwhich a bit forged in the machine will have a straight edge.

2. In a cutter bit forging machine, a rotatable carrier, means forrotating the carrier,

. said carrier having a die surface on the periphery thereof and havinga stock receiving socket adjacent the die, a forging roller cooperatingwith the carrier and adapted to move toward and away from the carrier,and

means for effecting the movement of the forging roller toward and awayfrom the carrier in synchronism with the passage of the socket in thecarrier past the roller.

3. In a cutter bit forging machine, a rotatable carrier, means forrotating the carrier, said carrier having a die surface on the peripherythereof and having a stock receiving socket adjacent the die, a forgingroller cooperating with the carrier and adapted to move toward and awayfrom the carrier, means for effecting the movement of the forgingrollertoward and away from the carrier in synchronism with the passageof the socket in the carrier past the roller, and a second rolleradjustably fixed with respect to the carrier located in advance of thefirst, said second named roller being adapted to roughly forge thearticle to shape, said first named roller being adapted toform asubstantially straight edge on the cutter bit.

4. A machine for forging cutter bits comprising a rotatable carrierhaving a plurality of stock receiving sockets therein with die blocks onthe periphery thereof adjacent each socket, means for rotating thecarrier, a forging roller located at one point about the periphery ofthe carrier for cooperation with the die blocks thereon, and automaticmeans for varying the position of the forging roller disk having .aplurality of stock receiving applying increased pressure to said secondroller during the initial movement of each socket and thereunder, andadjusting means for varying the pressure of each forging roll.

7. In a cutter bit forging machine, a continuous carrier having aplurality of sockets therein with a forging die adjacent each socket, aplurality of forging rollers cooperating with the carrier and past whichthe carrier is advanced to successively move the sockets therebeneath,and means for applying increased pressure to one of said forging rollersduring a portion of the travel of each socket therepast.

8. In a cutter bit forging machine, a continuous carrier having aplurality of sockets therein with a forging die adjacent each socket,said sockets being provided for the purpose of holding pieces of stockto be forged, means for intermittently rotating the carrier, a forgingroll cooperatively disposed with reference to the periphery of thecarrier and adapted to cooperate with the dies on the carrier forshaping the stock, said forging roller being movable toward and awayfrom the stock, and means for synchronizing the movement of the forgingroller with the movement of'the carrier.

In testimony whereof I have hereunto set my hand.

CARL J. ANGSTROM.

with respect to the disk to apply a variable 7 pressure to each piece ofstock as it engages the roller.

5. In a machine for forging bits, a carrier disk having a plurality ofstock receiving sockets in the periphery thereof and having forging dieslocated adjacent each socket, means for intermittently rotating thecarrier disk, a forging roll located at a point about the periphery ofthe disk for cooperation with the die blocks thereon and beneath whichthe die blocks are successively moved,

a second roll following the first, and means for applying increasedpressure to said second roller during the initial movement of eachsocket and thereunder.

6. In a machine for forging bits, a carrier

